High Wind in Hawaii, January 5 to 6, 2013

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST FRI JAN 4 2013

.SYNOPSIS...
STRONG TRADES WILL KEEP WET AND BREEZY CONDITIONS ACROSS THE ISLANDS
THROUGH THE WEEKEND WITH SHOWERS FAVORING WINDWARD AND MAUKA AREAS.
THE STRONG WINDS WILL BE ABLE TO PUSH SOME OF THE SHOWERS OVER
LEEWARD AREAS AT TIMES. THE TRADES ARE EXPECTED TO GRADUALLY
DIMINISH EARLY NEXT WEEK.

&&

.DISCUSSION...
STRONG HIGH PRESSURE NORTH OF THE ISLANDS WILL KEEP BRINGING STRONG
TRADES THROUGH THE WEEKEND WITH PERIODS OF BREEZY AND LOCALLY WINDY
CONDITIONS ACROSS THE STATE. ABUNDANT MOISTURE EMBEDDED IN THE
TRADES WILL KEEP PRODUCING SHOWERS...FAVORING WINDWARD AND MAUKA
AREAS. BUT THE STRONG TRADES WILL BE ABLE TO PUSH SOME OF THE
SHOWERS BEYOND THE MOUNTAIN RANGES AND INTO LEEWARD AREAS AT TIMES.
A WIND ADVISORY REMAINS IN EFFECT FOR ALL THE MAIN HAWAIIAN ISLANDS
DUE TO THE STRONG AND GUSTY WINDS. ALSO...A HIGH WIND WARNING IS IN
EFFECT FOR THE HALEAKALA SUMMIT AREA WHERE WINDS MAY REACH THE
40-45 MPH RANGE WITH EVEN HIGHER GUSTS.

AN UPPER LEVEL TROUGH IS BEEN DEPICTED BY MODEL GUIDANCE DEVELOPING
ACROSS THE NPAC AND REACHING SOUTHWARD SAT-SAT NIGHT...BRINGING A
COLD AIR MASS AND INCREASING INSTABILITY NEAR THE BIG ISLAND AND
THE WATERS TO THE EAST. THUS...THE OFFICIAL FORECAST WILL CONTINUE
TO CARRY A SLIGHT CHANCE OF THUNDERSTORMS SAT AFTERNOON AND SATURDAY
EVENING. TEMPERATURES WILL BE COLD ENOUGH FOR SOME SNOW TO FALL ON
THE BIG ISLAND SUMMITS.

MODELS SHOW THAT PRESSURE GRADIENTS SHOULD BEGIN RELAXING BY LATE
SUN AND INTO EARLY NEXT WEEK WITH THE TRADES GRADUALLY DECREASING
AS THE HIGH PRESSURE SYSTEM MOVES AWAY FROM THE ISLANDS. SHOWER
ACTIVITY WILL DECREASE BUT STILL EXPECTING LOW CLOUDS AND PASSING
SHOWERS FAVORING WINDWARD AND MAUKA AREAS. BY MID WEEK...GLOBAL
MODELS DIVERGE IN THEIR SOLUTIONS WITH GFS STILL TRYING TO PUSH A
FROPA ACROSS THE AREA...WHILE ECMWF KEEPS THE ONGOING TRADE WIND
REGIME IN PLACE. FOR NOW...THE LONG TERM FORECAST WILL CONTINUE TO
FOLLOW THE LATER SOLUTION WITH TRADE WIND WEATHER REMAINING IN PLACE
THROUGH THE END OF NEXT WEEK.

&&

.MARINE...
THE STRONG TRADE WIND FLOW WILL CONTINUE TO PRODUCE VERY ROUGH AND
CHOPPY CONDITIONS ALONG EAST FACING SHORES THROUGH THE WEEKEND. A
HIGH SURF ADVISORY WILL BE IN EFFECT UNTIL SUNDAY EVENING FOR EAST
FACING SHORES.

A SMALL CRAFT ADVISORY REMAINS POSTED FOR ALL HAWAIIAN COASTAL
WATERS DUE TO WINDS AND SEAS...EXCEPT FOR THE PAILOLO AND ALENUIHAHA
CHANNELS...AND THE WATERS SOUTH OF THE BIG ISLAND WHERE A GALE
WARNING IS NOW IN EFFECT. A RECENT SCATTEROMETER PASS INDICATED GALE
FORCE WINDS IN THE ALENUIHAHA CHANNEL.

&&

.AVIATION...
A TIGHT N-S PRESSURE GRADIENT WILL MAINTAIN STRONG ENE TRADE WINDS.
AIRMET TANGO ISSUED FOR MOD TURB BELOW 8 KFT LEE OF THE MTNS AND
BETWEEN FL300 AND FL400 DUE TO AN UPPER LEVEL TROUGH. SFC WSPD OF 30
KT THROUGH WINDIER AREAS OF ALL ISLANDS. AIRMET SIERRA
ISSUED FOR MT OBSC OF ALL ISLANDS ABOVE 025...EXCEPT KAUAI.

A BANDS OF SHOWERY LOW CLOUDS ASSOCIATED WITH THE REMNANT OF A FRONT
WILL CONTINUE TO PRODUCE WIDESPREAD MVFR CONDITIONS MAINLY ALONG
WINDWARD SLOPES.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH WIND WARNING UNTIL 6 PM HST SATURDAY FOR HALEAKALA SUMMIT.

WIND ADVISORY UNTIL 6 PM HST SATURDAY THE FOR REMAINDER OF THE STATE.

HIGH SURF ADVISORY UNTIL 6 PM HST SUNDAY FOR EAST FACING SHORES.

GALE WARNING UNTIL 6 PM HST SATURDAY FOR PAILOLO CHANNEL-
ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG ISLAND
SOUTHEAST WATERS.

SMALL CRAFT ADVISORY UNTIL 6 PM HST SATURDAY FOR ALL OTHER COASTAL
WATERS.

&&

SYNOPSIS/DISCUSSION/MARINE...REYNES
AVIATION...MORRISON